The present invention relates to a filtration apparatus for filtering gaseous contaminants out of an air stream. More specifically, the present invention relates to a rotary adsorption apparatus for filtering of volatile constituents from a gaseous stream.
In recent times, it has become necessary for many industries to provide methods of removing and/or reducing contaminates from a gaseous air stream. Thus, many air purification systems have been produced for removing or purifying of various gaseous contaminants.
A gaseous stream which is in need of purification is produced during operation of a manufacturing procedure or other job function. For instance, volatile constituents are commonly produced, in paint spray booths, during paint spraying operations. It is necessary to remove these volatile constituents prior to exhaustion of the air in the paint booth to the atmosphere. It is desirable to provide a purification system which can remain operational for extended periods of time, such that it does not substantially interfere with production operations. Such a purification apparatus would allow continued operation of the plant or the like without frequent and costly shutdown times for replacement or regenerating of the apparatus.
Adsorptive media, such as activated carbon and the like, has been used for some time to remove volatile constituents from a gaseous stream. These types of apparatuses have the advantage that the filtration element can be regenerated to produce added life to the apparatus. U.S. Pat. Nos. 4,778,422 to Dawson and 4,402,717 to Izumo et al. disclose such adsorptive filtering devices. U.S. Pat. No. 4,778,422 to Dawson shows an adsorption apparatus which is rotatably mounted such that the adsorption medium can be regenerated at the same time a gaseous stream is being purified. U.S. Pat. No. 4,402,717 to Izumo et al. discloses a similar apparatus that provides an axially directional flow of contaminated gas through a portion of an elongated cylindrical adsorption element, such that a portion of the adsorptive element may be regenerated during filtration of a gaseous stream.
While these patents have disclosed improvements in the art, there still remains the need to replace adsorptive elements when the adsorptive elements can no longer be regenerated. This requires replacement of an entire specifically designed adsorptive cartridge prior to continuing purification of the gaseous stream. Additionally, the volume occupied by these structures tends to be prohibitively large in light of the final volume flow of air treated.
In many of these prior structures it is necessary to provide a pre-filter sacrificial carbon bed which will take out high boiling point contaminants which may tend to load up the regeneratable bed, thus lessening its useful life. The necessity of such an external sacrificial bed adds greatly to the volume of the final assembly.
Thus, it is a goal in the art to provide replaceable adsorption elements, which can be readily and easily replaced when necessary. It has also been a goal in the art to reduce or eliminate the pre-filtering sacrificial bed to reduce space consumed by an adsorption apparatus. Additionally, it has been a goal in the art to provide an apparatus which will have improved airflow characteristics at lower total occupied volumes and be readily adaptable to existing duct work in paint spray booths and the like. It has also been a goal in the art to provide a more efficient method of removing volatile constituents from a gaseous stream without the disadvantages set forth above.